Question: What is the chemical compound of erythromycin when interacting with a significant drug?
Paraphrase: When interacting with a significant drug, what is the chemical compound of erythromycin?
SPARQL (Wikidata):  select distinct ?sbj where { ?sbj wdt:P769 wd:Q213511 . ?sbj wdt:P31 wd:Q11173 } 
Answer: clarithromycin, pimozide, azithromycin, droperidol, haloperidol, chlorpromazine, anagrelide, dronedarone, amiodarone, irinotecan, quinidine, sotalol, pentamidine, procainamide, lovastatin, terfenadine, ergotamine, sevoflurane, dihydroergotamine, flecainide, sulpiride, chloroquine, astemizole, escitalopram, domperidone, methylergonovine, moxifloxacin, disopyramide, cisapride, simvastatin, halofantrine, dofetilide, ibutilide, bepridil, mesoridazine, probucol, arsenic trioxide, cocaine, thioridazine